1. Field
The present application relates to an electronic apparatus to which an AC adaptor can be connected.
2. Description of Related Art
An electronic apparatus such as a notebook personal computer can operate with electric power supplied from a built-in battery or electric power supplied from an commercial power source via an AC adaptor. An AC adaptor is an apparatus that transforms a voltage (for example, 100 V) of a commercial power source to a voltage (for example, 16 V) suitable for an electronic apparatus such as a notebook personal computer.
Since such an AC adaptor is carried often with a notebook personal computer, reducing the size and the weight is preferred. For reducing size and weight of the AC adaptor, for example, the size of a transformer provided to the AC adaptor may be reduced. However, since the size of the transformer relies on the rating of the electronic apparatus such as a notebook personal computer to be connected, sometimes an extremely-downsized transformer cannot be adapted to the rating of the electronic apparatus. Under the circumstances, there is a limitation in reducing the size and weight of a transformer and an AC adaptor having the same while confirming to the rating of an electronic apparatus.
JP H11-215736 A and JP H11-215737 A each discloses a power supply device where the power source for supplying electric power to an optical disk apparatus can be selected from any of a personal computer, an AC adaptor and a battery, so as to decrease the importance of the battery, thereby reducing the size and weight of the optical disk apparatus.
However, none of the power supply devices disclosed by JP H11-215736 A and JP H11-215737 A can supply appropriate electric power to the optical disk apparatus in a case where an AC adaptor having a downsized transformer is connected to the power supply device. As a result, only an AC adaptor that is not downsized or light-weight can be connected, and thus it is difficult to improve the portability for carrying the optical disk apparatus and the AC adaptor together.